EXHIBIT 5.1

                          OPINION OF COOLEY GODWARD LLP
August 2, 2000

InterNAP Network Services Corporation
601 Union Street, Suite 1000
Seattle, WA 98101

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection
with the filing by InterNAP Network Services Corporation (the "Company") of a
Registration Statement on Form S-8 (the "Registration Statement") with the
Securities and Exchange Commission (the "Commission") covering up to 9,831,738
shares of the Company's Common Stock, $.001 par value (the "Shares"), for
issuance (i) pursuant to the Company's 1999 Equity Incentive Plan, 1999 Employee
Stock Purchase Plan and 2000 Non-Officer Equity Incentive Plan (collectively,
the "Plans"), and (ii) upon the exercise of outstanding options granted under
the Plans (the "Options").

In connection with this opinion, we have examined and relied upon the
Registration Statement and related Prospectus, the Company's Articles of
Incorporation, as amended, and Bylaws, as currently in effect, and the originals
or copies certified to our satisfaction of such records, documents,
certificates, memoranda and other instruments as in our judgment are necessary
or appropriate to enable us to render the opinion expressed below. We have
assumed the genuineness and authenticity of all documents submitted to us as
originals, the conformity to originals of all documents submitted to us as
copies thereof and the due execution and delivery of all documents where due
execution and delivery are a prerequisite to the effectiveness thereof.

On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the Shares, when sold and issued in accordance with the Registration
Statement, the Plan and the options to be granted thereunder will be validly
issued, fully paid and non-assessable.

We consent to the filing of this opinion as an exhibit to the Registration
Statement.

Very truly yours,

COOLEY GODWARD LLP


By:  /s/ Christopher W. Wright
   -----------------------------------------
         Christopher W. Wright